Emergency Radiology

We present a case of a 58-year-old female with anti-PD-1 immunotherapy-related small bowel perforation. The patient was on long-term therapy with nivolumab for metastatic non-small cell lung cancer. She presented to the emergency department with acute abdominal pain, in which the CT revealed a short segment of dilated distal ileum proximal to a very short segment of bowel with mural thickening and a perforation near the transition point. The patient underwent subsequent laparotomy, which confirmed the CT findings and revealed a short-segment of friable and dilated loop of distal ileum proximal to a stricture and a small perforation at the transition point. Pathological analysis revealed mural thickening at the site of stricture without evidence of malignancy with focal necrosis and perforation at the transition point. Bowel perforation in the setting of anti-PD-1 immunotherapy is rare, but life-threatening complication, and should be considered in oncology patients on immunotherapy presenting with severe abdominal pain.

The study aimed to evaluate the image quality in terms of signal-to-noise ratio (SNR) and dose to the lens of the eye and the other nearby organs from the CT brain scan using an automatic tube current modulation (ATCM) system with or without CT gantry tilt is needed. An anthropomorphic phantom was scanned with different settings including use of different ATCM, fixed tube current time product (mAs) settings and degree angles of gantry tilt. Gafchromic film XR-QA2 was used to measure absorbed dose of the organs. Relative doses and SNR for the various scan settings were compared with the reference setting of the fixed 330 mAs. Average absorbed dose for the lens of the eyes varied from 8.7 to 21.7 mGy. The use of the ATCM system with the gantry tilt resulted in up to 60% decrease in the dose to the lens of the eye. SNR significantly decreased while tilting the gantry using the fixed mAs techniques, compared to that of the reference setting. However, there were no statistical significant differences for SNRs between the reference setting and all ATCM settings. Compared to the reference setting of the fixed effective mAs, using the ATCM system and appropriate tilting, the gantry resulted in a substantial decrease in the dose to the lens of the eye while preserving signal-to-noise ratio. CT brain examination should be carefully controlled to optimize dose for lens of the eye and image quality of the examination.

We sought to determine the diagnostic accuracy of magnetic resonance (MR) imaging compared with computed tomography (CT) and ultrasound (US) when evaluating for five common pelvic pathologies among women presenting to the emergency department (ED) with right lower quadrant abdominal pain. This prospective, single-center study was conducted at an academic ED as a sub-analysis of a direct comparison of the diagnostic accuracy of CT and MR in the evaluation of appendicitis. Patients were eligible for participation in the parent study if they were at least 12 years old and had a CT performed for evaluation of possible appendicitis. In the current study, only female patients who also underwent pelvic US were included. Three radiologists independently interpreted each MR examination specifically for the presence of pelvic pathology, knowing that patients had initially undergone imaging evaluation for possible appendicitis. The determination of an independent expert panel of two radiologists and one emergency physician based on surgical pathology, comprehensive chart review, clinical information, and follow-up phone calls served as the reference standard. Test characteristics of MR, CT, and US were calculated based on this; the main outcome measure was the summary sensitivity and specificity of MR versus CT and US. Forty-one participants were included with a mean age of 27.6 ± 10.8 years. The MR consensus interpretation had an overall sensitivity and specificity of 57.1% (CI 38.8–75.5%) and 97.2% (CI 94.7–99.6%) respectively, for detecting any of the five pelvic pathologies. By comparison, CT exhibited sensitivity and specificity of 66.7% (CI 50.0–83.5%) and 98.3% (CI 96.4–100.0%) while it was 64.3% (CI 46.5–82.0%) and 97.7% (CI 95.6–99.9%) for US, respectively. No significant differences were identified when comparing these modalities. Overall, Fleiss’ kappa interrater reliability value for MR interpretation was 0.75, corresponding to substantial agreement between the three readers. In women who might otherwise undergo multiple imaging tests to evaluate gastrointestinal versus pelvic pathologies, our data suggest that MR may be an acceptable first-line imaging test.

The objective of this study is to measure the accuracy of multidetector CT angiography (MD CTA) in the detection of vascular abnormalities in patients ≤40 years with spontaneous intraparenchymal hemorrhage (IPH) presenting to the emergency department. After institutional review board approval, a retrospective study was performed of 43 consecutive patients ≤40 years, who presented to our emergency department with IPH and that were evaluated with MD CTA. MD CTA images were reviewed by a neuroradiologist to determine IPH location, presence of a vascular abnormality, and associated extraparenchymal hemorrhage. Diagnostic accuracy was measured comparing it to the available reference standards, which included conventional catheter angiogram (CCA), surgical macroscopic findings, and pathology results. Medical records were reviewed for risk factors and correlation with final diagnosis. MD CTA demonstrated an accuracy of 97.7%, with a sensitivity of 96.4% (95% CI 0.79–0.99) and a specificity of 100% (95% CI 0.74–0.99) for the detection of vascular abnormalities in young patients with IPH. Additionally, MD CTA had a PPV of 100%, and the NPV 93.8% in this population. Of the 43 patients included in the study, 28 patients (65%) had a causative vascular etiology for the IPH. Among the 28 patients with vascular etiologies for the IPH, 11 had an AVM (39.2%), nine a ruptured aneurysm (32.14%), seven dural venous sinus thrombosis (25%), and one had vasculitis (3.57%). MD CTA is highly accurate in the detection of vascular abnormalities in the setting of IPH, which as a group represents the most frequent etiology of IPH among patients age ≤40 years. MD CTA performed in the Emergency Department provides accurate, rapid and critical presurgical and premedical treatment information in young patients with IPH.

Purpose: To assess the utilization of non-contrast head computed tomography (HCT) in clinically stable patients who were involved in motor vehicle collisions. Our goal is to identify patients in whom HCT may be safely excluded without altering clinical outcome. Methods: Adult, front-seat passengers were retrospectively examined. All clinically stable patients involved in motor vehicle collisions and who subsequently underwent HCT were studied to determine the factors that increased the statistical likelihood of a negative examination. Seven factors relevant to passenger safety or clinical outcomes were measured. Results: Eighteen of the 206 patients who met criteria for our study had positive HCT findings. Front-seat passengers were more likely to suffer traumatic head injury than drivers. Both Glasgow Coma Scale (GCS) and Injury Severity Score (ISS) individually had statistically significant correlations with positive HCT findings. Thirteen of the 18 patients had GCS scores of 13–15. Seatbelts, rollover collisions, gender, and airbag deployment demonstrated relatively decreased predictive values. Conclusion: The ISS emerged as the single most reliable predictor of positive HCT findings. Regarding multiple variable effects, the combinations of ISS and patient position or GCS and patient position are the most statistically significant clinical factors in identifying patients in whom HCT may be safely excluded.

The purpose of this study was to access the accuracy of multi-detector-row computed tomography (MDCT) in diagnosing injuries in hemodynamically stable abdominal gunshot wound victims (AGWV). Triple-contrast MDCT was performed in hemodynamically stable AGWV during a 20-month prospective diagnostic accuracy study. Thirty-one patients (30 males, 1 female; mean age, 24.3 years) were evaluated by two radiologists for evidence of injury to solid and hollow organs, vascular structures, urinary bladder, diaphragm, fractures, and general findings (free fluid, pneumoperitoneum, and mesentery lesions). All of the patients underwent laparotomy, and prevalence, sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. No statistically significant differences between radiologists were found. All of the solid and hollow organ lesions, vascular lesions, and general findings were detected. One of the four urinary bladder lesions was missed by MDCT, leading in this case to a sensitivity of 75%, specificity of 100%, positive predictive value of 100%, negative predictive value of 96.4%, and accuracy of 96.8% (p = 0.001). One of the eight diaphragm lesions was missed by MDCT, and its sensitivity was 87.5%, specificity was 100%, positive predictive value was 100%, negative predictive value was 95.8%, and accuracy was 96.8% (p < 0.001). Fractures were diagnosed in 74.4% of the patients (24 of 31). Fourteen (43.2%) patients demonstrated non-therapeutic laparotomy, in which minor lesions could have been managed conservatively. We concluded that MDCT is an accurate imaging method in evaluating selected AGWV, providing trusted information for emergency room physicians.

This article reviews the role of magnetic resonance imaging in evaluating suspected or known lower limb fractures of the hip, knee, ankle, and forefoot.

While acute appendicitis is a common and important clinical problem, a variety of other disease processes can affect the appendix. Simple and perforated appendicitis, tip appendicitis, and stump appendicitis share a common clinical presentation including anorexia, right lower quadrant pain, and fever. By imaging, most cases of acute appendicitis exhibit luminal dilation, wall thickening, and periappendiceal inflammatory stranding. In tip appendicitis, these changes are isolated to the distal appendix, often with an obstructing appendicolith. Perforated appendicitis can exhibit mural discontinuity, periappendiceal abscess, and/or extraluminal appendicoliths. After appendectomy, the appendiceal remnant or “stump” can become inflamed, often necessitating repeat surgery. Inflammatory bowel disease can involve the terminal ileum, secondarily involving the appendix, or may primarily involve the appendix. Patient symptoms can be chronic in such cases, and mucosal hyperenhancement is a pronounced imaging feature. In asymptomatic patients without appendiceal inflammation, the appendix can be dilated by intraluminal material such as inspissated succus in cystic fibrosis or mucus from benign appendiceal mucocele. Finally, neoplasms such as typical appendiceal carcinoid tumor and mucinous adenocarcinoma can involve the appendix. Carcinoids are often small and incidentally discovered at pathologic examination, while malignant mucinous adenocarcinoma tends to present with advanced disease including pseudomyxoma peritonei. Cecal cancers can also obstruct the appendiceal lumen and cause acute appendicitis; an astute radiologist can recognize this prospectively and facilitate definitive resection (right hemicolectomy) at the time of surgery. Attention to mural features, cecal configuration, and periappendiceal inflammation is essential to the correct prospective diagnosis of complicated appendicitis and less common appendiceal pathologies.

Ultrasound is a rapid, widely available and inexpensive imaging modality for the evaluation of the ankle and hindfoot. Ultrasonography can be performed in acute, semiacute and chronic conditions. Ankle injuries can be evaluated with ultrasound combined with X-rays. In the emergency room, acute trauma of ankle and hindfoot is an important indication for ultrasound.